# What's my error trying to plot

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Lauren Fuentes
on 30 Jun 2020

Commented: Lauren Fuentes
on 1 Jul 2020

Fs = 100;

t = (1:100)/Fs;

s1 = sin(2*pi*t*5); s2=sin(2*pi*t*15); s3=sin(2*pi*t*30);

s = s1+s2+s3;

[b,a] = ellip(4,0.1,40,[10 20]*2/Fs);

[H,w] = freqz(b,a,512) and plot(w*Fs/(2*pi),abs(H));

sf = filter(b,a,s);

S = fft(s,512);

SF = fft(sf,512);

w = (0:255)/256*(Fs/2);

plot(w,abs([S(1:256)' SF(1:256)']))

##### 2 Comments

Adam Danz
on 30 Jun 2020

### Accepted Answer

Gurpreet Singh
on 30 Jun 2020

Hi Lauren,

This error is occurring because of line 6. There should be delimeter instead of "and".

It should be as follows.

Fs = 100;

t = (1:100)/Fs;

s1 = sin(2*pi*t*5); s2=sin(2*pi*t*15); s3=sin(2*pi*t*30);

s = s1+s2+s3;

[b,a] = ellip(4,0.1,40,[10 20]*2/Fs);

[H,w] = freqz(b,a,512) ; plot(w*Fs/(2*pi),abs(H));

sf = filter(b,a,s);

S = fft(s,512);

SF = fft(sf,512);

w = (0:255)/256*(Fs/2);

plot(w,abs([S(1:256)' SF(1:256)']))

##### 0 Comments

### More Answers (1)

SC
on 30 Jun 2020

is the error you are getting:

"Invalid expression. Check for missing multiplication operator,

missing or unbalanced delimiters, or other syntax error. To

construct matrices, use brackets instead of parentheses." ?

This maybe because of 'and' in your code at line:6

Try the following:

Fs = 100;

t = (1:100)/Fs;

s1 = sin(2*pi*t*5); s2=sin(2*pi*t*15); s3=sin(2*pi*t*30);

s = s1+s2+s3;

[b,a] = ellip(4,0.1,40,[10 20]*2/Fs);

[H,w] = freqz(b,a,512);

plot(w*Fs/(2*pi),abs(H));

sf = filter(b,a,s);

S = fft(s,512);

SF = fft(sf,512);

w = (0:255)/256*(Fs/2);

plot(w,abs([S(1:256)' SF(1:256)']))

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